Insulated control



Nov. 13, 1928. v

' A. o. AUSTIN msummn CONTROL Fi led Aug. 11,, 1924 :5 Sheets-Sheet '1.

, INVENTOR Byfill iqfl mam A TTORNEYS Nov. 13, 1928.

A. O. AUSTIN INSULATED CONTROL Filed A 11 1924 3 Sheets-Sheet 2 FiyJ INVENTOR BY ATTORNEYS Nov. 13, 192&

o. AUSTIN msuu'ran com'RoL Filed Aug. 11, 1924 iii; 4466 5 Shts-Sheet 3 INVENTOR a ATTQRNEYS Patented Nov. 1 928.

" UNITED STATES 1,691,751 PATENT OFFICE.

ARTHUR AUSTIN, OF BABIBEBTON, OHIO, ASSIGNOR, BY MESNE ASSIGNMENTS, TO THE OHIO BRASS COMPANY, OF MANSFIELD, OHIO, A CORPORATION 01 NEW'J'EBSEY.

nw'suna'rnn common.

Application ma August 11, 1924. Serial ml'zarsoa- This invention relates to means for controlling the discharge from electrodes connected withthe dielectric members of insulators in order to permit higher voltages to be impressed on the insulators without producing flash-over.

' The invention is exemplified in the combination and arran ement of parts shown in the accompanying rawings and described in m the following specification, and it 1s more particularly pointed out in the appending claims- I Inthe drawings- 1 is an elevation with parts m sec- 1 5 tion showing an insulator having one embodiment of the present invention.

Fig. 2 is a top plan view of the insulator shown in Fig. 1.

Figs. 3, 4, 5 and 6 a're top plan views of nsulators showing modified forms of the invention.

Fig. 7 is a section on line 7-7 of F1g. 5. Fi s. 8 and 9 areplan and elevation respectively, of an insulator showing a modlfied form of the invention,

Figs. 10,11, and 12 are sections on lines 10-10, 1111 and 1212 respectively of Fi 8.

. forming insulated controls used to raise an or revent the flash-over of insulators, the

device may be readily made when attached separately to a pin type or suspension msulator. When made as a part of the insulator itself, however, the construction. is more difficult. In many cases an insulated control such as disclosed in my prior 1 a tent Not 1,521,743, January 6, 1925, whilegiying very fine results 'may be expensive or inconvenient to install and a less expensive method:

' '-oflproducingresults ma be desired.

11 the case of bus insu ators as well as pin types and suspension ty es, there may be a strong tendency to disc ar e, from the ,cap along the upper surface. I an annular-r ng. is raised, it is ordinarily necessary to cover I this with a water shedor to fill the resulting depression with some suitable compoundso that water will not free and destroy the 1n- Y sulator. damage due to freezing in-.

w creases-the cost of. the insulator and unless themecessary" protective measures are carefull carried out may create a hazard, particu arlyin localities where there is rain likely'to be followed by freezing.

to bus insulators, it may be used in ma-ny higher v0 to Fig. 1 shows a'bus insulator equipped with a draining type of insulated control which may be applied directly'to the upper weather surface 0 a pin or suspension insulator. While the method is particularly applicable types of pin insulators as well as suspensioninsulators. Fig. 1 shows thefadaption of the method to a bus or switch insulator. In Fig. 1 the insulating elements or members 10, 11 and 12 are shown in half section half elevation. The insulator is mounted on a pin 13 and has a cap 14 cemented to its head.

Under electrical stressthe discharge tends to L start from the lower edge of the cap at, the point 15. This discharge is partly caused by the high stress and the charging current of the member 10. If, however, an insulating ring or barrier 16 is raised from the surface, this chargingcurrent will tend to be arrested and the voltage can be raised until discharge will take place from some otherpoint higher up on the cap or willbe forced over the bar rier thereby increasing the volta e which may be carried Without causing-.fi ash-over. The barriers on the upper side not only tend to prevent an accumulative discharge out over the flange which ma greatly lower the flash-over of the insri ator, particularl under high frequency surges, but the lengt of leakage path is increased as well as the surface resistance. The streamers inthe, groove act as conductors and tendto screen the other portions in their vicinity so that the voltage may be raised without causing discharge. It is evident, howeyer, that water will be trappedin the grooveunless open-'- ings are provided at or near the low point' or unless the insulator is in an approximately horizontal position in which case no provision is necessary. If a, groove-or notch is cut in the barrier 16, a streamer starting from the loweredge of the cap at 15 may discharge I v through this opening or groove and the performance of the insula'tor will not be appre-. cia-bly improved and may possibly be'poorer in some cases. By making the groove, however, -in a tangential or spiral direction and Y close to a chargedfsurface, it is possible-to utilirze the'principle of the insulated hontrol' and prevent discharge along the groove. While the length of the groove is a factor, it is not nearly as important as the mutual effect of a charged surfaceat the same or slightly tage, which tends to suppressthe streamer in the groove. The proximity of 110 the groove to the charged surface maintains a potential throughout the groove approximating the potential of the charged surface so that there is no considerable drop in potential along the groove. Since the surface resistance along thegroove is high and the potential drop relatively low due to the proximity of the charged surface the current in the groove will be kept down.

One arrangement is clearly shown in Fig. 2 which is the plan view of theupper face of the insulator shown in Fig. 1. A streamer starting from the edge of the cap 14 will tend to flow along the groove 17. As this groove, however, is very close to the inside of the barrier adjacent to the cap, the charging current will be largely supplied from the cap or'con ducting streamers on the inside of the barrier so' that there will be a strong tendency to repress the steamer tending to flow out the groove 17. It is the suppression of the streamer that is desired. In order that this be accomplished, to the best advantage, it is necessary to make the path of discharge close to a charged surface or one, which is adjacent to the electrode or conducting surface. Owing to this principle, it is possible to. ob-

tain the benefit of an insulated control malt ing same integral with the part of the insulator, and, at the same time forming an insulator which will not trap water. There are a number of ways of accomplishing the result. The general principle, however, remains. the same in that the path of discharge through a draining slot or opening is approximately parallel or close to a charged surface or recesswhich is drained.

Fig.3 shows another form. In this case .the groove 16 is drained by. a hole 18 which centric ribs or flanges 19 and 20 spaced from one another andproviding a channel 21 adjacent the cap 14 and a channel 22 concen-' tric with the channel 21 but separate therefrom by the flange 19. In order to. drain the channel 21 there is provided a plurality of openings 23 distributed in spaced relation and extending through the base of the flange 191 Similar openings 24 are provided through ing through the opening 23 will be directed the flange v2O for draining the channel 22 but the .openings 24 are arranged instaggered relation to the openings 23 so that these open-- ingsdo not provide a continuous path for discharge streamers.

It will be apparent that a streamer passalong thechannel 22: in close proximity to the charged surface formed by the flange on the cap 14 but separated from this surface by the flange 19. The proximity of the charged flange and the streamers emanating therefrom to the channel 22 will tend to stop the 26. These passages, as will be seen rom the drawings, are arranged in staggered relation to one another so that the operation will be similar to the device shown in Fig. 5.

There are many ways in which an insulated control may be applied to the upper surface of an insulator and stilldrain water which may be entrapped between the insulating member and the conducting surface. It is essential, however, that the surface tending to discharge be covered with the insulating member and;' furthermore, that the draining passage be screened with a charged surface or have a long path not directly in the line of normal discharge.

Fig. 8 shows a plan view of the top of the insulatorshown in Fig. 9, the insulator being the same general type as'that shown in Fig. 1. A discharge is prevented from the lower edge of the cap 14 by bafile 27, 28 and 29. One method of draining the enclosure is by an open slot 29'. Discharge along this is prevented by slots 30 adjacent to slot 29, the slots 30 being conducting in their lower por- 7 .tion, the conducting material being in electrical contact with the cap 14, either through direct connection or by discharge. The conducting slots 30 screen the slot 29 and unless the path 29 has a relatively low resistance,

discharge will be prevented along this path.

Fig.10 shows a cross section along the line 10.10 of Fig. 8. In some cases where it is desirable to screen the slot for a considerable distance, charged surfaces may be carried out to a point where there is danger of discharging from them. This may be prevented by the method shown in Fig. 11 which is a sec tion on the line 1111-. In this case the charged screening surfaces 31, although open and in contact with the cap 14 at their inner surface, are closed at their outer end forming a closed insulated control on each side of the draining slot 32.

Fig. 12 is a section on the line 12-12 and shows another method of screening the discharge. Opening 33 is a hole in this instance. The discharge is prevented along the hole by a coated surface of cylindrical form extending part way around the discharge hole 33.

This charged surface is shown by 34. It is not necessary that thecharged or screening surfaces be in electrical contact with the cap or electrode if their arrangement is such that they will become charged surfaces before discharge will take place through the-slot or opening. In order to be most efiective, however, it is generally advisable tozplace conducting material or coating in these surfaces to insure an efiicient screening action.

I claim. v v d 1.- An insulator comprising a dielectric member, an electrode, and means providing separate aths of discharge from said-electrode, said paths being arranged adjacent one another so that the discharge along one path will be diminished by the influence of the discharge'in an adjacent path.

, said e ectrode, sai

from one another while the portion of one 2. An insulator comprising a dielectric member, an electrode, and means for providing a lurality of aths of discharge from paths being insulated path more removed from said electrode is arranged closely adjacent the portion of another path closer to said electrode.

3. An insulator comprising a dielectric member, an electrode, and means providing a plurality of discharge paths from said electrode, remote rtions of each of said paths bein arrangedzlosely adjacent a ortion of anot er path j ac'entportions of saidpaths bein separated from one another by a dielectric arrier. v

4. An insulator comprising an electrode,a

.dielectricmember connected with said electrode and having a surface thereof extending away from said electrode and barriers of dielectric material formed-on said surface to provide restricted paths of discharge from said electrode, said paths having open end portions and havin portions thereof between said electrode an open end portions subjected to-the influence of a high potential for diminishing discharge through said open end portions, said electrode being arranged to extend into the space at the sides of said barriers.

a 5. An insulator comprising an electrode, a dielectric member connected with said electrodeand havin a surface extending away from said electrode and means on said surface providing a plurality of restricted paths.

of discharge from said electrode, said .paths having drainage openings and having por;

tions thereof between said drainage openings and said electrode arranged in close rox- .imity to said electrode but separated t ere-.

from by dielectric material, said'electrode being arranged to extend-into position adj acent open endsof saidpaths.

6. An insulator comprising an electrode, a dielectric member connected with said electrode and'having a surface extending therefrom and means on said surface providing a pluralityof paths of discharge from said ings and each path -having a portion thereof electrode, saidpaths having drainage opencloser to said electro e, the ad- August, A. 1924.

between said electrode and its drainage opening arranged adjacent a portion of another path closer to said electrode, the adjacent portion of said paths being separated by dielectric material, said electrode being arranged to extend into position adjacent openends of said paths;

' 7. An insulator comprising an electrode, a dielectric member connected with said electrode and having asurface extending there-- from and ribs on said surface forming paths for discharge from said electrode, there berate over-lapping paths of discha e from said electrode, the lowermost portio of said paths being open to provide drainage.

9. An insulator comprisin an electrode, a dielectric member. connecte with said electrode and having a surface extending therefrom anda plurality of'spirallyarranged ribs on said surface, said ribs bein arranged in over-lapping relation to rovlde a plu-.

rality of paths of discharge rom said electrode which over-lap one another while permitting drainage at the outer ends ofthe paths ormed by said ribs.

a dielectric barrier for re'venting discharge from said fitting, there eing a drainage pas- 10. An insulator having a charged fitting, I

sage through said barrier, said fitting forming a charged surface adjacent said passage but insulated therefrom, the inner end of said passage being open adjacent said fitting. 11. An insulator having a dielectric barrier thereon provided with a draina e passage, said passage being shielded by a c arged surface, one end of said passage being open adjacent said surface andhaving direct con nection therewith.

12. An insulator having a fitting connected therewith, a dielectric barrier for restricting ing a raina'ge passage therethrough, said passage being shielded by a. charged surface separated from said passage by dielectric material, said drainage passage; being open directl adj acent said fitting and communicating irectly with said 'fittin I In testimony whereof I have si ned myv .Ldischar e from said fitting, said barrier havname to, this specification on this 6t day of ARTHUR onus'rml 

